num·mu·lite (nŭm'yə-līt') n. A large, coin-shaped, fossil foraminifer of the genus Nummulites, widely distributed in limestone formations from the Eocene Epoch to the Miocene Epoch of the Cenozoic.
[From New Latin Nummulītēs, type genus, from Latin nummulus, diminutive of nummus, coin, probably from Greek nomimos, customary, legal; see nem- in Indo-European roots.] num'mu·lit'ic (-lĭt'ĭk) adj.